Refrigerating apparatus



Nov. 3, 1953 A. s. ALISON ETAL 2,657,550

REFRIGERATING APPARATUS Filed Jan. 12, 1951 z-iz1wcs=sneet 1 INVENTORS Alexander Szkinegflldson Ronaldflifirion ATTORNEYS Nov. 3., 1953 Filed Jan. 12, 1951 A. 5. ALISON ET AL REFRIGERATING APPARATUS 3 Sheets-Sheet 2 )E LIL INVENTORS Alexander J'Zdnqy A 255071 Ronald A bherzzorn/ Mora, m

ATTORNEYS Patented Nov. 3, 1953 UNITED STATES PATENT OFFICE REFRIGERATIN G APPARATUS Alexander Sidney Alison, Norbury, London, and Ronald Atherton, Chelsea, London, England, assignors to General Foods Corporation, New York, N. Y., a corporation of Delaware Application January 12, 1951, Serial No. 205,692

3 Claims. 'f

This invention relates to refrigerating apparatus of the multiplate type for quick-freezing foodstuffs. Apparatus of this type comprises a vertical stack of relatively separable refrigerating plates which are movable toward and away from one another so that they can be opened to receive the products to be frozen between them and then closed to contact the products during freezing.

Previously refrigerating apparatus have been designed so that the refrigerant supply and discharge connections to each plate are disposed on the rear faces of the stacks and accessible from the rear of the stack. In the preferred form of this apparatus laterally spaced refrigerant supply and discharge connections are located on each of the plates adjacent opposite sides of the stack and at its rear. The refrigerant supply and discharge headers are inset laterally with respect to the discharge and supply connections respectively. Both headers are also spaced rearwardly of the stack, one header being rearwardly offset with respect to the other. Two vertically disposed sets of flexible conduits means extend laterally in opposite directions from the supply and discharge headers to said supply and discharge connections respectively, one of said sets being located intermediate the other set and the stack.

This arrangement of conduit means is crowded into a narrow space between the rear face of the stack and rear wall of the casing enclosing the stack. As a result of this crowded arrangement the conduit means can be connected by detachable unions only to the headers. The other ends of the conduits have to be secured over nipples screwed inside the refrigerant supply and discharge connections on each plate and clamped to said nipples by steel bands since there is no room between the nearest header and the plate to allow the insertion of a spanner over the nut of a union for detaching that union for maintenance purposes. The removal of the nipples from the connectionson the plates for purposes of replacing conduits is often very difiicult, particularly when as frequently happens, the nipples have become rusty. In the latter event, the removal of the nipple can only be effected by removing the appropriate plate of the stack. Furthermore, it is difficult to ensure that all the steel bands clamping the flexible conduit means are sufiiciently tight to prevent refrigerant leakage. When the refrigerant is liquid ammonia", a leakage in only one conduit due to an insufiiciently tight steel band can be a serious disadvantage since it would necessitate immediate attention and the stoppage of the whole apparatus with consequent loss of output.

Another defect of the above-described arrangement of conduit means arises from the fact that a coating of ice builds up on the outside of the flexible conduits during the operation of this apparatus. This coating of ice can increase in thickness to such an extent that when the plates are in the closed position it contacts similar coatings on the conduits immediately above and below it. When two ice coatings contact, they tend to adhere to one another, thus necessitating an increase in the force normally required to separate the plates, in view of the fact that the force now has to overcome the adherence of the ice coatings. In breaking the contact between ice coatings on consecutive conduits there is a danger of straining these conduits. To avoid the formation of too thick a coating of ice on each conduit, frequent de-frosting of the apparatus has to be resorted to, and this frequent de-frosting means a further loss of output.

It is an object of the present invention to provide refrigerating apparatus of the type described above in which the arrangement of refrigerant supply and discharge conduit means is such as to avoid the above-mentioned disadvantages.

The present invention provides a refrigerating apparatus for quick-freezing foodstuffs which comprises a vertical stack of relatively separable refrigerating plates, refrigerant supply and discharge headers disposed at the rear of said stack and refrigerant inlet and outlet connections located on the rear face of each plate, and connected to said refrigerant supply and discharge headers respectively by flexible conduits in such a manner that the conduits are in two sets, one set comprising conduits connected to every other plate of the stack being capable of flexing in a plane substantially parallel to the rear face of the stack and the other set comprising the conduits connected to the remaining plates of the stack being capable of flexing in a plane substantially parallel to said first mentioned plane and located between it and the rear face of the stack.

The said headers may be located close to the mid point of the stack and the said connections at the corners of each plate of the stack. Preferably the headers are located at the rear corners supply header side of and closely juxtaposed to the mid point of the rear face of the stack.

Each flexible conduit in the arrangement of the present invention should be of such a length that when the plates are in the closed position the ice coating on the flexed conduit does not contact that on the conduit which. isimmediately below itandin the same plane.

Each conduit may also be connected to its respective plate through a detachable union, since.

the points of connection to the plates, are now spaced laterally some distance away from the headers which do not therefore interfere with the use of a spanner on theunion for remoyal, purposes.

The invention is particularly applicable to re frigerating apparatus containing up to about ten plates. When the apparatus'contains' more than about ten plates the flexible conduits have to. be

made correspondingly longer to accommodate the greater movement of the uppermost plates which occurs during closure. The increase in length which occurs in such larger apparatusrnay result in. the ice coating on adjacent conduits .of the respective sets contactingwhen the plates close, so thatfreezing -upof the top conduits is not com.- pletely avoided.

' The invention will now bedescribed with referencetothe accompanying drawings in which:

Fig-1 is an elevation of the rearend of refrigerating apparatus according to the invention showing the plates in the open position.

Fig. 2 is the corresponding elevation to that shown in Fig. 1 showing the plates in the closed position.

Fig. 3 is a plan of the rear part of the arrangement, shown in Figs. 1 and 2.

Fig l is a. plan of the rear part of the arrangementshown in Figs. l and 2- illustrating the lowermost conduit, and

Fig. 5 is a plan View of a plate for use in the arrangement of Figs. 1 and 2.

Referring to the drawings a stack of horizontal plates l movable vertically relative to one another by hydraulic means (not shown) are located within acasing 2, the bottom plate, I of the stack being stationary. A refrigerant supply header 3- is located atone rear cornerof thestaok and isconnected to a source of refrigerant, which is not shown. A refrigerant discharge header 4 is,l ocated at the other rear corner of the stack. Each. header is provided with a set of straight branchesiand a setof elbow branches 6 at intervals. along. its lengthin such a manner that a straight branch 5 is always adjacent an. elbow branch 6. Both sets, ofbranches are internally threaded at their open ends to receive an externally. threaded. straight union 1 carrying a length of rubber hose 8 or 8.

Each of the plates has internally threaded inlet and, outlet connections 9 and 1.0 respectively, both of which are on the refrigerant supply header side and closely juxtaposed to the mid point A of each plate, as shown in Figs. 1, 2, and 5. This arrangementcompensates for the greater strains set up in the thicker hose which have to be used as discharge conduits. The spacing of the branches 5 and 6 on the headers 3 and 4 may be such. that the vertical distances of each connection. 9 or ill above its respective branch 5 or; 6 when the plates are in the open position is approximately equal to its vertical distance below this branch when the plates. are in the closed position. Alternatively, the spacing of the branches 5, and: 6- maybe 50- chosen. as to. ensure that as many hoses as possible are of equal length, thereby facilitating renewal of any hose which may subsequently show some defect, by replacing it with a hose of standard length. Again the spacing of the branches 5 and 6 on the headers may be so chosen as to strike a balance between, or satisfy thetWQ alternative featureszrnentioned above.

The shape of the refrigerant channels inside each plate is shown in Fig. 5 and the refrigerant travels along the two paths indicated by the two' sets off-arrows a: and y. The inlet and outlet connectionson the; plates which are connected to hosesfl. attached. to the straight branches 5 of the headers carry short adaptors II which are externally threaded at both ends and screwed into the, inlet and. outlet connections. Elbow bend internally threaded unions l2 are fitted to the othe'r end of the hoses 8 and screwed over the free ends of the adaptors H, the length of which is: .Such: that. when: he. hose. 8. is connected. to, the header and. outlet or inlet cQnn ctiQnS t sp allel. to; the rear face Of: the plate. as in Fig. 3. Similarlyv the. inlet and outlet, connections. on the plates, which, are, connected to hoses .8 attached to the elbow. branches. 6:o f theheaders carry. long adaptors l3 into the free ends of which more elbow. bend;internallythreaded.unions l2 fittedto the hoses 8' are secured. The length of these long adaptors. I3 is. such thatthe: set of hoses. 8' connecting the elbow. branches 6 on theL headers to. the platesarealso parallel tothe rearface of the stack and located outside thehoses. 8 connecting the elbow branches. 5. to the plates, as in Fig. 3. The refrigerant inlet and outlets 9;, II) on the stationary'bottom plate I" of the stack are connected. tothe bottom of the headers 3 and '2 through tworigid pipes 14, straight branches 5 and straight unions 1', l5 and short adaptors II as inFig. 4.

When the refrigerating apparatus is operated toclose the plates, the hoses. assume the positions shown in Fig. 2. In this position each hose 8 flexes downwardly-in a plane parallel to the rear face of the stack.- The ice coating on this hose does not, however, contact that on the hose 8' on the next plate below since the latter hose is ina different plane. Similarly theice coating on hose 8 when this hose flexes does not touch that on-the hose 8 onthe plate-below since this hose 8' though in the same plane as the above mentioned hosell" is a different plane from hose- B. Thus contact between the ice coatings on consecutive hoses is avoided thereby eliminatingthe freezing togetheroftwo consecutive hoses. It is clear from Figs. 1 and 2 that all the unions 1 and [2 are readily accessibleand that the hexagonal nuts oneach union can be embraced by a spanner without interference by either of the headers or hoses.

It should be noted however that this arrangement of hoses is most suitable when the stack contains a small number of plates for example l ssthant nplates. h mor th nten p at s are. connected, upwby hoses arranged. according to the invention, difficulties may be encountered due to. the-amount of flexing undergone bythe hoses connectedv to the upper plates of the stack since the bigger the stack .the greater the distance moved; by its, upper plates. The, distance moved by the-upperplatesin the case of stacks containing-for example sixteenplates may also necessitate the use of a. long; length of hose which might flex to suchan extentas to cause, itsice'coating to touch that of the hose connected to the nextbut-one plate-below and freeze thereto.

What is claimed is:

I v 1. A refrigerating apparatus for quick-freezing foodstufis which comprises a vertical stack of relatively separable refrigerating plates, refrigerant supply and discharge headers disposed at the rear of said stack and refrigerant inlet and outlet connections located on the rear face of each plate, and two groups of flexible conduits one connecting said plate inlet connections with said supply header and the other connecting said plate outlet connections with said discharge header, each group of conduits being divided into two sets, one set comprising conduits connected to every other plate of the stack being capable of flexing in a plane substantially parallel to the rear face of the stack and the other set comprising the conduits connected to the remaining plates of the stack being capable of flexing in a plane substantially parallel to said first mentioned plane and located between it and the rear face of the stack, each of said flexible conduits being of such a length that when the plates are in the closed position any ice coating on a flexed conduit does not contact that on the conduit which is immediately below it in the same plane.

2. A refrigerating apparatus as claimed in claim 1 in which said refrigerant supply and discharge headers are located at the rear corners of the stack and said refrigerant outlet and inlet connections are both on the refrigerant supply header side of and closely juxtaposed to the mid point of the rear face of the stack.

3. A refrigerating apparatus as claimed in claim 1 in which each flexible conduit is connected to its respective plate through a detachable union.

ALEXANDER SIDNEY ALISON. RONALD A'IHER'I'ON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,283,923 Hall May 26, 1942 2,315,768 Burnette Apr. 6, 1943 2,329,746 Davison Sept. 21, 1943 2,485,509 Raye Oct. 18, 1949 

